Rouse Model with Internal Friction:  A Coarse Grained Framework for Single Biopolymer Dynamics

2007 ◽  
Vol 40 (18) ◽  
pp. 6770-6777 ◽  
Author(s):  
Bhavin S. Khatri ◽  
Tom C. B. McLeish
2021 ◽  
Vol 65 (5) ◽  
pp. 903-923
Author(s):  
R. Kailasham ◽  
Rajarshi Chakrabarti ◽  
J. Ravi Prakash

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Guang-jin Wang ◽  
Xiang-yun Kong ◽  
Chun-he Yang

The researchers cannot control the composition and structure of coarse grained soil in the indoor experiment because the granular particles of different size have the characteristics of random distribution and no sorting. Therefore, on the basis of the laboratory tests with the coarse grained soil, the HHC-Granular model, which could simulate the no sorting and random distribution of different size particles in the coarse-grained soil, was developed by use of cellular automata method. Meanwhile, the triaxial numerical simulation experiments of coarse grained soil were finished with the different composition and structure soil, and the variation of shear strength was discussed. The results showed that the internal friction angle was likely to reduce with the increasing of gravel contents in the coarse-grained soil, but the mean internal friction angle significantly increased with the increment of gravel contents. It indicated that the gravel contents of shear bands were the major factor affecting the shear strength.


2016 ◽  
Vol 61 (3) ◽  
pp. 1723-1732 ◽  
Author(s):  
Weijuan Li ◽  
Shengshi Zhao ◽  
Hengyi Zhang ◽  
Xiaolong Jin

AbstractIn the present work, specimens prepared from coarse grained low carbon steel with different prestrains were baked and then, their bake hardening (BH) property and internal friction were determined. TEM was used to characterize the dislocation structure in BH treated samples. The measurements of internal friction in prestrained samples and baked samples were carried out using a multifunctional internal friction apparatus. The results indicate that, in coarse grained low carbon steel, the bake hardening properties (BH values) were negative, which were increased by increasing the prestrain from 2 to 5%, and then were decreased by increasing the prestrain from 5 to 10%. In the specimen with prestrain 5%, the BH value reached the maximum value and the height of Snoek-Köster peak was observed to be the maximum alike. With increasing the prestrain, both of the BH value and Snoek-Köster peak heights are similarly varied. It is concluded that Snoek-Köster and dislocation-enhanced Snoek peaks, caused by the interactions between interstitial solute carbon atoms and dislocations, can be used in further development of the bake hardening steels.


2022 ◽  
Vol 12 (1) ◽  
pp. 447
Author(s):  
Shuya Li ◽  
Tiancheng Wang ◽  
Hao Wang ◽  
Mingjie Jiang ◽  
Jungao Zhu

Shear strength is an essential index for the evaluation of soil stability. Test results of the shear strength of scaled coarse-grained soil (CGS for short) are usually not able to accurately reflect the actual properties and behaviors of in situ CGS due to the scale effect. Therefore, this study focuses on the influence of the scale effect on the shear strength of scaled CGS, which has an important theoretical significance and application for the strength estimation of CGS in high earth-rock dam engineering. According to previous studies, the main cause of the scale effect for scaled CGS is the variation of the gradation structure as well as the maximum particle size (dmax), in which the gradation structure as a characteristic parameter can be expressed by the gradation area (S). A total of 24 groups of test soil samples with different gradations were designed by changing the maximum particle size dmax and gradation area S. Direct shear tests were conducted in this study to quantitatively explore the effect of the gradation structure and the maximum particle size on the shear strength of CGS. Test results suggest that the shear strength indexes (i.e., the cohesion and internal friction angle) of CGS present an increasing trend with the improvement of the maximum particle size dmax, and thus a logarithmic function relationship among c, φ, and dmax is presented. Both cohesion (c) and internal friction angle (φ) are negatively related to the gradation area (S) in most cases. As a result, an empirical relationship between c, φ, and S is established based on the test results. Furthermore, a new prediction model of shear strength of CGS considering the scale effect is proposed, and the accuracy of this model is verified through the test results provided by relevant literature. Finally, the applicability of this model to different types of CGS is discussed.


2010 ◽  
Vol 143-144 ◽  
pp. 873-878
Author(s):  
Guang Jin Wang ◽  
Xiang Yun Kong ◽  
Yi Lei Gu ◽  
Chun He Yang

The strength parameters of granular coarse-grained soil are the critical factor that affects the stability of ultra-high dump. The soil particles of different size have no sorting and random distribution, which leads to the initial fabric of sample grain uncontrolled in the laboratory test of coarse-grained soil, therefore, only relying on the laboratory testing is difficult to obtain the reliable strength parameters of coarse-grained soil. Based on Cellular Automata method, combining the laboratory triaxial tests of coarse-grained soil developed the HHC-CA model which generated the coarse-grained soil samples of different initial fabric of grain to characterize the heterogeneous and random distribution of coarse-grained soil grain group. Then by means of FLAC3D, conducting triaxial numerical simulation tests of coarse-grained soil and discussing the relationship between the gravel contents of samples shear band and samples and internal friction angle. Moreover, the shear strength model for different coarse-grained contents is established. Numerical simulation results indicated that the relationship between internal friction angle of coarse-grained soil and gravel contents of samples shear band were increasing function in the same size grading. According to the increasing of samples gravel contents, the internal friction angle might reduce, but the mean internal friction angle significantly increased with the increment of samples gravel contents.


2014 ◽  
Vol 496-500 ◽  
pp. 2469-2473
Author(s):  
Guo Dong Deng ◽  
Jia Sheng Zhang ◽  
Xiong Shi ◽  
Fei Meng ◽  
Liang Liang Song ◽  
...  

One-way shearing test of the coarse-grained soils and the reinforced earth was carried out under different normal stresses. The one-way shearing curves of coarse-grained soils and reinforced earth are similar. The changed curves of normal direction deformation with the shearing distance of coarse-grained soils and reinforced earth are also similar. Trend of the curve for the normal direction deformation and the reinforced earth is shrink at first and then expand continually. Under different vertical stresses, the difference of the curve for the normal direction shift and the reinforced shift is larger. Compared with raw coarse-grained soils, the cohesive force (c) of the reinforced earth increased, but the angle internal friction (φ) decreased for the reason that the articulation effect between the grilling, and the coarse-grained soils was reduced in the progress of shearing. So, the anti-shearing strength was decreased.


Soft Matter ◽  
2021 ◽  
Author(s):  
Ramalingam Kailasham ◽  
Rajarshi Chakrabarti ◽  
Ravi Prakash Jagadeeshan

The Rouse model with internal friction (RIF), a widely used theoretical framework to interpret the effects of internal friction on conformational transitions in biomolecules, is shown to be an approximate...


2018 ◽  
Vol 22 (1) ◽  
pp. 65-71
Author(s):  
Junfu Lu ◽  
Di Li ◽  
Xiaoqiang Xue ◽  
Shenlin Ling

Sandy pebble stratum is a typical discrete particle unstable stratum, mainly consisting of sand and pebble. However, the effect of coarse-grained content on the stability of stratum is not clear. This paper defined the sandy pebble soil of different coarse-grained content in Chengdu City, Sichuan Province, China as the research object. Research on macro-mesomechanical properties of sandy pebble soil of different coarse-grained content was carried out using the method combining the indoor large-scale triaxial test of coarse-grained soil with the discrete element numerical triaxial test. The research results showed that the stress-strain curve of sandy pebble soil exhibited strain softening with the increase of coarse-grained content; when the confining pressure was the same, the stress peak increased and the strain when the peak was reached decreased gradually with the increase of coarse-grained content. It revealed the functional relationship between coarse-grained content and mechanical indexes of sandy pebble soil such as internal friction angle and cohesion. The internal friction angle and cohesion of sandy pebble soil linearly increased with the rise of coarse-grained material; it proposed the particle discrete element micro parameters of sandy pebble soil of different coarse-grained content, including contact modulus, friction coefficient, particle stiffness ratio, contact bond strength. The research results provided the theoretical support for the new design and construction of sandy pebble stratum project. 


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
J. M. Walsh ◽  
K. P. Gumz ◽  
J. C. Whittles ◽  
B. H. Kear

During a routine examination of the microstructure of rapidly solidified IN-100 powder, produced by a newly-developed centrifugal atomization process1, essentially two distinct types of microstructure were identified. When a high melt superheat is maintained during atomization, the powder particles are predominantly coarse-grained, equiaxed or columnar, with distinctly dendritic microstructures, Figs, la and 4a. On the other hand, when the melt superheat is reduced by increasing the heat flow to the disc of the rotary atomizer, the powder particles are predominantly microcrystalline in character, with typically one dendrite per grain, Figs, lb and 4b. In what follows, evidence is presented that strongly supports the view that the unusual microcrystalline structure has its origin in dendrite erosion occurring in a 'mushy zone' of dynamic solidification on the disc of the rotary atomizer.The critical observations were made on atomized material that had undergone 'splat-quenching' on previously solidified, chilled substrate particles.


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